Got a reply off the US site:
Hi Mark,
This is what I get on my 97 GXE Sentra B14. Imperial measurements only, no metric on my tape, sorry.
Width at base windscreen to corners 54 1/2
Width at front to corners above headlights 51 7/8
Length at center following contour, 38 3/8 ( ignoring dent, this is pretty accurate, the dent is on one side of center.)
Length of side from corner by windscreen to the corner above headlight, following contour, 40
Hope this answers your question enough to know if you can go forward.
How much are the CF bonnets anyway?